It is often necessary to measure the average, in contrast to peak power of a given signal. Typically, this has been accomplished for alternating-current ("AC") signals, especially at radio-frequencies, with a diode detector circuit. In a diode detector circuit the signal whose power is to be measured is placed across a diode while the diode is biased to be in its "square-law" region. As long as the oscillations from the signal do not drive the dime out of the square-law region, the voltage across the diode is indicative (e.g., proportional) of the power derived from the signal. When, however, the signal to be measured is complex (i.e., has multiple sinusoidal components) the respective sinusoidal components can constructively interfere, thus pushing the diode out of the square-law region and rendering the circuit inaccurate. Furthermore, the diode detector circuit has the disadvantage that the accuracy with which the circuit can measure the power derived from the signal deteriorates with changes in the ambient temperature.